The present invention relates to golf balls such as two-piece solid golf balls or three-piece solid golf balls which are composed of a core enclosed by a cover of one or more layers.
Various cover materials consisting largely of ionomer resins have been disclosed in the prior art. Such cover materials are often intended to provide the golf ball with a higher rebound and an increased carry. In this connection, reference may be made to many known documents, including U.S. Pat. No. 6,616,552, U.S. Pat. No. 6,613,843, U.S. Pat. No. 6,232,400, JP-A 10-231400 and JP-A 2004-231746.
However, when the hardness of the ionomer resin used as the cover material is increased, the durability of the golf ball to repeated impact often diminishes. Hence, in prior-art golf balls, it has been difficult to achieve both a good rebound resilience and a good durability to impact.
Aside from the problem of durability to repeated impact, such golf balls have had a poor scuff resistance, with fraying and scuffing of the ball surface often arising. In addition, when the ball is used over an extended period of time, it has a tendency to discolor. In particular, because white is often used as the surface color in golf balls, even slight yellowing or other discoloration of the ball surface will lower the quality of the ball and make it unattractive. A need thus exists for a solution to such problems.